I was having a one day trip for Venice and I can tell you that is the best choice for the value. You can see all the important attractions on your own and you got a good schedule that can suit everyone.
No one welcomes you or speaks at all. Don't expect any sightseeing info. We had a party of 10, purchased 2-day access tickets (accepts both electronic and paper vouchers). Second day, in spite of the fact that we had all electronic proof, 4 of our 10 were denied access to boat without paper. Rude, snotty people to deal with. Cost 200Euros to get to next port then 'home'. There are better choices than this, with much better schedules.
We loved this tour, we can't recommend it enough.. It does a huge lap of Venice including St Marco Square, Lido beach and Murano. It takes a while to do but if you plan on visiting these beautiful places then the hop on hop off is the way to go
Do not waste your money on this. There is no commentary on the sights. It is just a taxi service basically. Viator should not be promoting this tour. There are numerous other options to move around Venice and be entertained better.
Easy and less expensive way to get around Venice then cabs and less crowded then some of the water buses. Some of the ports were closed and did not know in advance we would be have to get off at one port and wait for another boat. Not that big an inconvenience and did not take that long, just not where we wanted to go and were surprised because not informed.
Also instructions for pickup was slightly incorrect but in the general area and easy to find.